M100
NGC 4321 · Galaxy in Coma Berenices
- Magnitude
- 9.3
- Size
- 7′ × 6′
- Effective surface brightness
- 22.0 mag/arcsec²
- Best months
- Mar, Apr, May
- Declination
- +16°
- Filter
- None (broadband target)
A grand-design spiral in Coma Berenices, one of the biggest in the Virgo cluster.
Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
How long with each smart telescope
| Telescope | In frame | Bortle 3 (rural) | Bortle 5 (suburban) | Bortle 7 (urban edge) |
|---|---|---|---|---|
| ZWO Seestar S5010 s subs | 16% | 56 min334 subs | 1 h 29 min536 subs | 3 h 57 min1,421 subs |
| ZWO Seestar S50 Pro10 s subs | 8% | 1 h 02 min371 subs | 1 h 38 min590 subs | 4 h 18 min1,547 subs |
| ZWO Seestar S3010 s subs | 10% | 1 h 03 min376 subs | 1 h 36 min578 subs | 4 h 04 min1,463 subs |
| ZWO Seestar S30 Pro10 s subs | 5% | 1 h 06 min398 subs | 1 h 45 min628 subs | 4 h 32 min1,635 subs |
| DwarfLab DWARF 315 s subs | 7% | 1 h 13 min293 subs | 2 h 05 min501 subs | 5 h 53 min1,413 subs |
| DwarfLab DWARF mini15 s subs | 10% | 55 min220 subs | 1 h 29 min355 subs | 3 h 56 min945 subs |
| DwarfLab Draco30 s subs | 9% | 45 min90 subs | 1 h 13 min146 subs | 3 h 16 min392 subs |
| DwarfLab DWARF II15 s subs | 7% | 4 h 03 min973 subs | 5 h 37 min1,348 subs | 12 h2,987 subs |
| Vaonis Vespera II10 s subs | 8% | 56 min334 subs | 1 h 29 min536 subs | 3 h 57 min1,421 subs |
| Vaonis Vespera Pro10 s subs | 7% | 2 h 16 min814 subs | 3 h 27 min1,240 subs | 8 h 37 min3,100 subs |
| Vaonis Vespera 310 s subs | 8% | 53 min316 subs | 1 h 25 min511 subs | 3 h 47 min1,361 subs |
| Vaonis Vespera Pro 210 s subs | 7% | 2 h 08 min768 subs | 3 h 16 min1,177 subs | 8 h 14 min2,964 subs |
| Unistellar eQuinox 24 s subs | 20% | 1 h 14 min1,107 subs | 1 h 35 min1,422 subs | 3 h 07 min2,801 subs |
| Unistellar Odyssey4 s subs | 21% | 6 h 32 min5,878 subs | 7 h 48 min7,026 subs | 13 h12,043 subs |
| Celestron Origin10 s subs | 14% | 13 min79 subs | 23 min137 subs | 1 h 05 min388 subs |
| Celestron Origin Mark II10 s subs | 16% | 16 min99 subs | 30 min182 subs | 1 h 30 min543 subs |
Imaging the galaxy
Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.
Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.
Per-telescope pages
- How long to image the M100 with the ZWO Seestar S50
- How long to image the M100 with the ZWO Seestar S50 Pro
- How long to image the M100 with the ZWO Seestar S30
- How long to image the M100 with the ZWO Seestar S30 Pro
- How long to image the M100 with the DwarfLab DWARF 3
- How long to image the M100 with the DwarfLab DWARF mini
- How long to image the M100 with the DwarfLab Draco
- How long to image the M100 with the DwarfLab DWARF II
- How long to image the M100 with the Vaonis Vespera II
- How long to image the M100 with the Vaonis Vespera Pro
- How long to image the M100 with the Vaonis Vespera 3
- How long to image the M100 with the Vaonis Vespera Pro 2
- How long to image the M100 with the Unistellar eQuinox 2
- How long to image the M100 with the Unistellar Odyssey
- How long to image the M100 with the Celestron Origin
- How long to image the M100 with the Celestron Origin Mark II